Conventionally, there has been known an automatic developing system of developing a photographic sensitized material provided with a series of treating tanks each filled with a certain treating liquid therein in the order from upstream to downstream in the direction of feeding the sensitized material, e.g., a developing tank filled with a developing liquid, a bleaching tank filled with a bleaching liquid, a fixing tank filled with a fixing liquid, and a stabilizing tank filled with a stabilizing liquid. In such an automatic developing system, subtanks such as a developing subtank filled with a developing liquid, a bleaching subtank filled with a bleaching liquid, a fixing subtank filled with a fixing liquid, and a stabilizing subtank filled with a stabilizing liquid are provided in such a manner as to communicate with the corresponding treating tank in order to circulate the treating liquid in the communicating treating tank and the subtank.
In particular, a plural number of fixing tanks and stabilizing tanks and a plural number of fixing subtanks and stabilizing subtanks are provided to suppress contamination of the fixing liquid and the stabilizing liquid by the treating liquid that has been adhered to the surface of the sensitized material in the process prior to the fixing/stabilizing process.
Fresh developing liquid and bleaching liquid are replenished into the developing subtank and the bleaching subtank respectively, and the developing liquid and the bleaching liquid in the respective treating tanks are drained outside. More specifically, the fixing subtank and the stabilizing subtank that are located on the downstream in the feeding direction are replenished with fresh fixing liquid and stabilizing liquid, respectively, and the fixing liquid and the stabilizing liquid are drained from the fixing tank and the stabilizing tank that are located on the upstream side, respectively. Thereby, the fixing liquid and the stabilizing liquid in the downstream subtank flow into the upstream subtank.
In the automatic developing system having the above construction, a transport rack is provided in each of the treating tanks to feed the roll of sensitized material from upstream to downstream in the treating tanks each filled with a treating liquid to sequentially perform a developing operation.
Observing the fixing tank/subtank, the bleaching liquid having a greater specific gravity than the fixing liquid is adhered to the surface of the sensitized material in the bleaching tank and carried into the fixing tank. Accordingly, the upstream fixing tank/subtank, which are closer to the bleaching tank, contain the fixing liquid having a greater specific gravity than the downstream fixing tank/subtank. When the fixing liquid having a smaller specific gravity in the downstream fixing subtank flows into the upstream fixing subtank through the liquid level, the lighter fixing liquid supplied from the downstream fixing subtank does not mix well with the heavier fixing liquid in the upstream fixing subtank due to the specific gravity difference.
The above phenomenon also occurs in the stabilizing tank and the stabilizing subtank. The fixing liquid having a greater specific gravity than the stabilizing liquid is adhered to the surface of the sensitized material in the fixing tank and carried into the stabilizing tank. Accordingly, the upstream stabilizing tank/subtank, which are closer to the fixing tank, contain the stabilizing liquid having a greater specific gravity than the downstream stabilizing tank/subtank. When the stabilizing liquid having a smaller specific gravity in the downstream stabilizing subtank flows into the upstream stabilizing subtank through the liquid level, the lighter stabilizing liquid supplied from the downstream stabilizing subtank does not mix well with the heavier stabilizing liquid in the upstream stabilizing subtank due to the specific gravity difference.
In order to prevent the above drawbacks, the conventional system is constructed such that a partition wall provided between the adjacent subtanks is formed with a through hole in a vertically intermediate portion thereof, and a liquid supply pipe is provided in the through hole to flow the treating liquid from the downstream subtank into the middle or a lower portion of the upstream subtank through the pipe with an attempt to mix the lighter treating liquid flowing from the downstream subtank with the heavier treating liquid in the upstream subtank.
The above idea of providing the pipe in the intermediate through hole in the partition wall separating the adjacent subtanks, however, is cumbersome in the aspect of plumbing operation. Further, in the case of integral molding of the treating tank and the subtank with a synthetic resin or its equivalent, the construction of a mold for the treating tank/subtank would be complex, because the through hole is formed in the vertically intermediate portion of the partition wall. This would raise the production cost of the system.
The present invention has been accomplished in view of the foregoing problems in the prior art and an object thereof is to provide an automatic developing system of developing a sensitized material that securely enables mixing of a treating liquid with a lighter specific gravity flowing from a downstream subtank with a treating liquid with a heavier specific gravity in an upstream subtank with a simple construction.